Improvement In Seismic Acquisition By 3D Global Offset Approach

The Global Offset acquisition technique is an innovative seismic methodology designed to acquire seismic data over an extended offset range. Standard seismic shots are recorded simultaneously by a conventional seismic layout and by densely spaced 3-C stand-alone stations deployed over the whole range of available offsets. This layout allows the acquisition of deep-penetrating turning rays and multifold wide-angle reflections without losing the benefits offered by the conventional near-vertical reflection seismic. The advantages of such an acquisition technique become evident in complex tectonic environments, where conventional seismic data often fail in providing useful information. Tomographic techniques applied to the transmitted and reflected wave fields allow the determination of detailed velocity models, while prestack depth migration of all the available offsets offers the potential to enhance depth images thanks to the high S/N ratio provided by the wide-angle reflections.